#define F_CPU 20000000UL  // 20 MHz CPU clock

#include <stdlib.h>
#include <avr/io.h>
#include <util/delay.h>

int main(void) 
{
	
	DDRC |= _BV(PC1); // set led pin to output
	
	PORTC |= _BV(PC1); // led on, pin high
	//PORTC &= ~_BV(PC1); //led off, pin low
         
        while (1)                       /* loop forever */
        {
                /* set PC1 on PORTC (digital high) and delay for 500mS */
                PORTC &= ~_BV(PC1);                
                _delay_ms(500);
                
                /*  PC1 on PORTC (digital 0) and delay for 500mS */
                PORTC |= _BV(PC1);
                _delay_ms(500);
        }
	
	
	return 0;
}
